Resistive random access memory (RRAM or ReRAM) relies on a class of materials that switch in a one-time event from a virgin insulating state to a low resistive state by way of a “forming” event. In the forming event, the device goes through “soft breakdown” in which a localized filament forms in a dielectric layer located between two electrodes. This filament shunts current through the filament to form a low resistance state. The RRAM switches from a low to a high resistive state (by disbanding the filament) and from a high to a low resistive state (by reforming the filament) by applying voltages of different polarities to the electrodes to switch the state. Thus, conventional RRAM can serve as a memory.